I have a 460 pc 4 bank charger that 2 banks have stopped charging on. Red light will come on soon as I plug it in, go off, and then yellow light will cycle between 25%, 50%, %75. The other two banks will charge all of my batteries when I swap the leads to them. Fuses are also good. Even changed them to make sure. Any body have any idea what else I could check? It’s out of warranty.